I *hate* the barn doors. I don't live in a barn, nor date farm animals. For some reason designers also put in frosted glass in these doors, which is terrible when you're not traveling solo. If anyone gets up in the middle of the night, you're waking up the entire room. Making matters worse are some hotels now have motion-activated lights in the bathroom which come on full-throttle; definitely NOT appreciated at 3am.
The barn doors also don't seem to block noise either.
I have to agree with @
itravelalot -- these things are probably great in the mock rooms, but your typical road dog wouldn't ever want it.